Wamsley Erin J, Antrobus John S
City College of New York, Department of Psychology, USA.
Neurobiol Learn Mem. 2009 Oct;92(3):283-91. doi: 10.1016/j.nlm.2009.02.012. Epub 2009 Feb 28.
Research in animals has demonstrated that patterns of neural activity first seen during waking experience are later "replayed" during sleep, in hippocampal and cortical networks. The characteristics of memory reactivation during human sleep, however, have not yet been fully described. Meanwhile, the possible relationship of dreaming to this "replay" of memories in the sleeping brain is entirely unknown. In the present study, we induced hippocampus-dependent memory retrieval during human sleep using a "trace conditioning" procedure. Prior to sleep, subjects underwent either trace (hippocampus-dependent) or delay (hippocampus-independent) auditory fear conditioning. Conditioned stimuli were then presented to subjects during non-REM sleep. Both delay-conditioned and trace-conditioned subjects exhibited conditioned EEG responses during post-training sleep. However, selectively in trace-conditioned subjects, fear-conditioned cues also affected the valence of dreamed emotions. These findings suggest that hippocampus-dependent learning is accessible during non-REM sleep, and that hippocampus-mediated memory reactivation may be expressed, not only through neural activity in the sleeping brain, but also within concomitant subjective experience.
对动物的研究表明，清醒时首次出现的神经活动模式，随后会在睡眠期间于海马体和皮层网络中被“重播”。然而，人类睡眠期间记忆再激活的特征尚未得到充分描述。与此同时，梦境与睡眠中大脑里这种记忆“重播”之间可能存在的关系完全未知。在本研究中，我们使用“痕迹条件反射”程序在人类睡眠期间诱发依赖海马体的记忆提取。在睡眠前，受试者接受了痕迹（依赖海马体）或延迟（不依赖海马体）听觉恐惧条件反射。然后在非快速眼动睡眠期间向受试者呈现条件刺激。延迟条件反射组和痕迹条件反射组的受试者在训练后的睡眠中均表现出条件性脑电图反应。然而，仅在痕迹条件反射组的受试者中，恐惧条件刺激也影响了梦境情绪的效价。这些发现表明，依赖海马体的学习在非快速眼动睡眠期间是可及的，并且海马体介导的记忆再激活不仅可以通过睡眠中大脑的神经活动来表达，还可以在伴随的主观体验中体现。
